Tampa Bay Buccaneers quarterback Tom Brady, widely considered the greatest player in NFL history, announced his retirement on Tuesday after a career during which he won a record seven Super Bowl championships.

The 44-year-old Brady spent 20 seasons with the New England Patriots, winning six Super Bowl titles, before relocating to Tampa Bay and leading the Bucs to a championship last season.

"I have always believed the sport of football is an 'all-in' proposition - if a 100% competitive commitment isn't there, you won't succeed, and success is what I love so much about our game," Brady wrote on Twitter.

"There is a physical, mental, and emotional challenge EVERY single day that has allowed me to maximize my highest potential. And I have tried my very best these past 22 years. There are no shortcuts to success on the field or in life.

"This is difficult for me to write, but here it goes: I am not going to make that competitive commitment anymore. I have loved my NFL career, and now it is time to focus my time and energy on other things that require my attention."